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><H1
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><A
NAME="CATALOG-PG-TRIGGER"
>45.42. <TT
CLASS="STRUCTNAME"
>pg_trigger</TT
></A
></H1
><P
>   The catalog <TT
CLASS="STRUCTNAME"
>pg_trigger</TT
> stores triggers on tables
   and views.
   See <A
HREF="sql-createtrigger.html"
>CREATE TRIGGER</A
>
   for more information.
  </P
><DIV
CLASS="TABLE"
><A
NAME="AEN88550"
></A
><P
><B
>Table 45-42. <TT
CLASS="STRUCTNAME"
>pg_trigger</TT
> Columns</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Name</TH
><TH
>Type</TH
><TH
>References</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgrelid</TT
></TD
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-class.html"
><TT
CLASS="STRUCTNAME"
>pg_class</TT
></A
>.oid</TT
></TD
><TD
>The table this trigger is on</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgname</TT
></TD
><TD
><TT
CLASS="TYPE"
>name</TT
></TD
><TD
>&nbsp;</TD
><TD
>Trigger name (must be unique among triggers of same table)</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgfoid</TT
></TD
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-proc.html"
><TT
CLASS="STRUCTNAME"
>pg_proc</TT
></A
>.oid</TT
></TD
><TD
>The function to be called</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgtype</TT
></TD
><TD
><TT
CLASS="TYPE"
>int2</TT
></TD
><TD
>&nbsp;</TD
><TD
>Bit mask identifying trigger firing conditions</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgenabled</TT
></TD
><TD
><TT
CLASS="TYPE"
>char</TT
></TD
><TD
>&nbsp;</TD
><TD
>       Controls in which <A
HREF="runtime-config-client.html#GUC-SESSION-REPLICATION-ROLE"
>session_replication_role</A
> modes
       the trigger fires.
       <TT
CLASS="LITERAL"
>O</TT
> = trigger fires in <SPAN
CLASS="QUOTE"
>"origin"</SPAN
> and <SPAN
CLASS="QUOTE"
>"local"</SPAN
> modes,
       <TT
CLASS="LITERAL"
>D</TT
> = trigger is disabled,
       <TT
CLASS="LITERAL"
>R</TT
> = trigger fires in <SPAN
CLASS="QUOTE"
>"replica"</SPAN
> mode,
       <TT
CLASS="LITERAL"
>A</TT
> = trigger fires always.
      </TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgisinternal</TT
></TD
><TD
><TT
CLASS="TYPE"
>bool</TT
></TD
><TD
>&nbsp;</TD
><TD
>True if trigger is internally generated (usually, to enforce
       the constraint identified by <TT
CLASS="STRUCTFIELD"
>tgconstraint</TT
>)</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgconstrrelid</TT
></TD
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-class.html"
><TT
CLASS="STRUCTNAME"
>pg_class</TT
></A
>.oid</TT
></TD
><TD
>The table referenced by a referential integrity constraint</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgconstrindid</TT
></TD
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-class.html"
><TT
CLASS="STRUCTNAME"
>pg_class</TT
></A
>.oid</TT
></TD
><TD
>The index supporting a unique, primary key, or referential integrity constraint</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgconstraint</TT
></TD
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-constraint.html"
><TT
CLASS="STRUCTNAME"
>pg_constraint</TT
></A
>.oid</TT
></TD
><TD
>The <TT
CLASS="STRUCTNAME"
>pg_constraint</TT
> entry associated with the trigger, if any</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgdeferrable</TT
></TD
><TD
><TT
CLASS="TYPE"
>bool</TT
></TD
><TD
>&nbsp;</TD
><TD
>True if constraint trigger is deferrable</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tginitdeferred</TT
></TD
><TD
><TT
CLASS="TYPE"
>bool</TT
></TD
><TD
>&nbsp;</TD
><TD
>True if constraint trigger is initially deferred</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgnargs</TT
></TD
><TD
><TT
CLASS="TYPE"
>int2</TT
></TD
><TD
>&nbsp;</TD
><TD
>Number of argument strings passed to trigger function</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgattr</TT
></TD
><TD
><TT
CLASS="TYPE"
>int2vector</TT
></TD
><TD
><TT
CLASS="LITERAL"
><A
HREF="catalog-pg-attribute.html"
><TT
CLASS="STRUCTNAME"
>pg_attribute</TT
></A
>.attnum</TT
></TD
><TD
>Column numbers, if trigger is column-specific; otherwise an
       empty array</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgargs</TT
></TD
><TD
><TT
CLASS="TYPE"
>bytea</TT
></TD
><TD
>&nbsp;</TD
><TD
>Argument strings to pass to trigger, each NULL-terminated</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>tgqual</TT
></TD
><TD
><TT
CLASS="TYPE"
>pg_node_tree</TT
></TD
><TD
>&nbsp;</TD
><TD
>Expression tree (in <CODE
CLASS="FUNCTION"
>nodeToString()</CODE
>
       representation) for the trigger's <TT
CLASS="LITERAL"
>WHEN</TT
> condition, or null
       if none</TD
></TR
></TBODY
></TABLE
></DIV
><P
>   Currently, column-specific triggering is supported only for
   <TT
CLASS="LITERAL"
>UPDATE</TT
> events, and so <TT
CLASS="STRUCTFIELD"
>tgattr</TT
> is relevant
   only for that event type.  <TT
CLASS="STRUCTFIELD"
>tgtype</TT
> might
   contain bits for other event types as well, but those are presumed
   to be table-wide regardless of what is in <TT
CLASS="STRUCTFIELD"
>tgattr</TT
>.
  </P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>    When <TT
CLASS="STRUCTFIELD"
>tgconstraint</TT
> is nonzero,
    <TT
CLASS="STRUCTFIELD"
>tgconstrrelid</TT
>, <TT
CLASS="STRUCTFIELD"
>tgconstrindid</TT
>,
    <TT
CLASS="STRUCTFIELD"
>tgdeferrable</TT
>, and <TT
CLASS="STRUCTFIELD"
>tginitdeferred</TT
> are
    largely redundant with the referenced <TT
CLASS="STRUCTNAME"
>pg_constraint</TT
> entry.
    However, it is possible for a non-deferrable trigger to be associated
    with a deferrable constraint: foreign key constraints can have some
    deferrable and some non-deferrable triggers.
   </P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>    <TT
CLASS="LITERAL"
>pg_class.relhastriggers</TT
>
    must be true if a relation has any triggers in this catalog.
   </P
></BLOCKQUOTE
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